81 citations · 526 across the 20 of their papers we have counts for
20 papers
Electromagnetic turbulence simulation of tokamak edge plasma dynamics and divertor heat load during thermal quench
Ben Zhu, Xue-qiao Xu, Xian-Zhu Tang
The edge plasma turbulence and transport dynamics, as well as the divertor power loads during the thermal quench phase of tokamak disruptions are numerically investigated with BOUT…
A fast algebraic multigrid solver and accurate discretization for highly anisotropic heat flux I: open field lines
Golo A. Wimmer, Ben S. Southworth, Thomas J. Gregory +1
We present a novel solver technique for the anisotropic heat flux equation, aimed at the high level of anisotropy seen in magnetic confinement fusion plasmas. Such problems pose tw…
Runaway electron current reconstitution after a non-axisymmetric magnetohydrodynamic flush
Christopher J. McDevitt, Xian-Zhu Tang
Benign termination of mega-ampere (MA) level runaway current has been convincingly demonstrated in recent JET and DIII-D experiments, establishing it as a leading candidate for run…
On the collisional damping of plasma velocity space instabilities
Yanzeng Zhang, Xian-Zhu Tang
For plasma velocity space instabilities driven by particle distributions significantly deviated from a Maxwellian, weak collisions can damp the instabilities by an amount that is s…
Structure preserving transport stabilized compatible finite element methods for magnetohydrodynamics
Golo A. Wimmer, Xianzhu Tang
We present compatible finite element space discretizations for the ideal compressible magnetohydrodynamic equations. The magnetic field is considered both in div- and curl-conformi…
Resolving the mystery of electron perpendicular temperature spike in the plasma sheath
Yanzeng Zhang, Yuzhi Li, Bhuvana Srinivasan +1
A large family of plasmas has collisional mean-free-path much longer than the non-neutral sheath width, which scales with the plasma Debye length. The plasmas, particularly the ele…
The constraint of plasma power balance on runaway avoidance
Christopher J. McDevitt, Xian-Zhu Tang, Christopher J. Fontes +2
In a post-thermal-quench plasma, mitigated or unmitigated, the plasma power balance is mostly between collisional or Ohmic heating and plasma radiative cooling. In a plasma of atom…
Cooling flow regime of a plasma thermal quench
Yanzeng Zhang, Jun Li, Xian-Zhu Tang
A large class of Laboratory, Space, and Astrophysical plasmas is nearly collisionless. When a localized energy or particle sink, for example, in the form of a radiative cooling spo…
Bohm criterion of plasma sheaths away from asymptotic limit
Yuzhi Li, Bhuvana Srinivasan, Yanzeng Zhang +1
The plasma exit flow speed at the sheath entrance is constrained by the Bohm criterion. The so-called Bohm speed regulates the plasma particle and power exhaust fluxes to the wall,…
Neural network representability of fully ionized plasma fluid model closures
Romit Maulik, Nathan A. Garland, Xian-Zhu Tang +1
The closure problem in fluid modeling is a well-known challenge to modelers aiming to accurately describe their system of interest. Over many years, analytic formulations in a wide…
Observation and modeling of interspecies ion separation in inertial confinement fusion implosions via imaging x-ray spectroscopy
T. R. Joshi, P. Hakel, S. C. Hsu +9
We report first direct experimental evidence of interspecies ion separation in direct-drive ICF experiments performed at the OMEGA laser facility via spectrally, temporally and spa…
Comparison of dust charging between Orbital-Motion-Limited theory and Particle-In-Cell simulations
Gian Luca Delzanno, Xian-Zhu Tang
The Orbital-Motion-Limited (OML) theory has been modified to predict the dust charge and the results were contrasted with the Whipple approximation [Tang and Delzanno, Phys. Plasma…
Observation of interspecies ion separation in inertial-confinement-fusion implosions
S. C. Hsu, T. R. Joshi, P. Hakel +9
We report direct experimental evidence of interspecies ion separation in direct-drive, inertial-confinement-fusion experiments on the OMEGA laser facility. These experiments, which…
Orbital-motion-limited theory of dust charging and plasma response
Xian-Zhu Tang, Gian Luca Delzanno
The foundational theory for dusty plasmas is the dust charging theory that provides the dust potential and charge arising from the dust interaction with a plasma. The most widely u…
Charging and heat collection by a positively charged dust grain in a plasma
Gian Luca Delzanno, Xian-Zhu Tang
Dust particulates immersed in a quasineutral plasma can emit electrons in several important applications. Once electron emission becomes strong enough, the dust enters the positive…
Reflection and implantation of low energy helium with tungsten surfaces
Valery Borovikov, Arthur F. Voter, Xian-Zhu Tang
Reflection and implantation of low energy helium (He) ions by tungsten (W) substrate are studied using molecular dynamics (MD) simulations. Motivated by the ITER divertor design, o…
Survivability of dust in tokamaks: dust transport in the divertor sheath
Gian Luca Delzanno, Xianzhu Tang
The survivability of dust being transported in the magnetized sheath near the divertor plate of a tokamak and its impact on the desired balance of erosion and redeposition for a st…
Thermo-diffusion in inertially confined plasmas
Grigory Kagan, Xian-Zhu Tang
In a plasma of multiple ion species, thermodynamic forces such as pressure and temperature gradients can drive ion species separation via inter-species diffusion. Unlike its neutra…
Electro-diffusion in a plasma with two ion species
Grigory Kagan, Xian-Zhu Tang
Electric field is a thermodynamic force that can drive collisional inter-ion-species transport in a multicomponent plasma. In an inertial confinement fusion (ICF) capsule, such tra…
Bounce-free spherical hydrodynamic implosion
Grigory Kagan, Xian-Zhu Tang, Scott C. Hsu +1
In a bounce-free spherical hydrodynamic implosion, the post-stagnation hot core plasma does not expand against the imploding flow. Such an implosion scheme has the advantage of imp…